Timepiece component, timepiece movement, timepiece, and method for manufacturing a timepiece component

Abstract

A timepiece component in which a balance spring made of a paramagnetic substance is high-strength welded to an inner stud. The timepiece component (46) includes an inner stud (44) fixed to a balance shaft, a balance spring (43) made of a paramagnetic substance, having an inner end portion (43a) fixed to the inner stud (44), and a fusion portion (60) in which the inner stud (44) and the balance spring (43) are fused to fix the inner stud (44) and the inner end portion (43a) to each other. The fusion portion (60) has a first fusion portion (60A) provided at a position on a first side in an axial direction of the inner end portion (43a), and a second fusion portion (60B) provided at a position on a second side in the axial direction of the inner end portion (43a).

Description

Technical Field

[0001] This invention relates to watch parts, watch movements, watches, and methods for manufacturing watch parts. Background Technology

[0002] Mechanical watches possess an escapement / regulating mechanism that controls the rotation of the barrel wheel, second wheel, third wheel, and fourth wheel, which constitute the watch's gear train. A typical escapement / regulating mechanism includes an escape wheel and a balance wheel and hairspring system. The balance wheel and hairspring system includes a balance wheel, a balance shaft, a hairspring, and an inner stud. The balance shaft serves as the center of rotation for the balance wheel. The inner stud is fixed to the balance shaft. The inner end of the spiral-shaped hairspring is fixed to the inner stud. The hairspring causes the balance wheel to reciprocate through expansion and contraction. It is known to fix the hairspring to the inner stud by welding (see, for example, Patent Documents 1 and 2).

[0003] [Prior Technology Documents] [Patent Literature] [Patent Document 1] Japanese Patent No. 7007109; [Patent Document 2] Swiss Patent Application Publication No. 468662. Summary of the Invention

[0004] [The problem the invention aims to solve] However, it is desirable to improve the welding strength of the inner stud and the hairspring. Laser welding is sometimes used as a welding method for the inner stud and the hairspring. In this case, if the heat input is increased to increase the melting range, the hairspring generally has a more slender cross-sectional shape than the inner stud, resulting in higher thermal resistance. The area around the weld point is heated in a concentrated manner, leading to coarsening of the crystals. Coarsening of the crystals in metallic materials easily causes a decrease in strength, especially in paramagnetic materials such as niobium alloys, which are prone to intergranular fracture (grain boundary breakage) due to coarsening of the crystals. Therefore, hairsprings made of niobium alloys are prone to breakage due to coarsening of the crystals, resulting in a significant decrease in strength. Therefore, when laser welding the inner stud and the hairspring, it is necessary to limit the heat input to the hairspring to suppress the decrease in the hairspring's own strength.

[0005] Furthermore, in niobium alloy hairsprings, due to the high melting point of niobium alloys and the aforementioned limitations on heat input, it is more difficult to form a deep weld compared to hairsprings made of Elingar alloys. Therefore, stress concentration caused by the wedge effect may reduce weld strength.

[0006] Furthermore, paramagnetic materials such as niobium alloys are used as hairsprings by forming an oxide film on their surface to compensate for temperature. When such a paramagnetic hairspring is welded to the inner stud, oxides accumulate at the end of the molten portion, thereby further increasing the wedge effect and easily reducing the weld strength.

[0007] Patent Document 1 discloses an invention that improves the adhesion strength of the hairspring by setting multiple weld joints between the hairspring and the inner stud. However, Patent Document 1 does not disclose or imply any decrease in weld strength due to the wedge effect, and the effect of improving the adhesion strength of the hairspring based on the invention described in Patent Document 1 is limited.

[0008] Furthermore, Patent Document 2 discloses an inner stud with an overhang shape covering the hairspring from both the top and bottom, and a method including welding to fix the inner stud and the hairspring. However, Patent Document 2 does not disclose the conditions suitable for laser welding of a hairspring with a paramagnetic structure having a coating on its surface. Additionally, in the invention described in Patent Document 2, the hairspring is fixed at multiple points throughout the entire circumference of the inner stud, which could potentially improve productivity.

[0009] Therefore, the present invention provides a watch part, a watch movement, a watch, and a method for manufacturing a watch part, wherein a paramagnetic hairspring is welded to an inner stud with high strength.

[0010] [Solutions for solving the problem] The first aspect of the present invention relates to a watch part comprising: an inner stud fixed to a balance shaft; a hairspring formed of a paramagnetic material having a fixed portion fixed to the inner stud; and a molten portion which is formed by melting the inner stud and the hairspring to fix the inner stud and the fixed portion to each other, the molten portion comprising: a first molten portion disposed at a position on a first side relative to the axial direction of the fixed portion; and a second molten portion disposed at a position on a second side relative to the axial direction of the fixed portion.

[0011] According to the first embodiment, the hairspring is fixed to the inner stud on both sides in the axial direction. Therefore, compared to a configuration where the hairspring is fixed to the inner stud via a single molten section, the amount of heat input to the hairspring during the formation of the first and second molten sections can be reduced, while simultaneously increasing the overall volume of the molten sections. This helps to suppress the decrease in the strength of the hairspring itself, and simultaneously improves the welding strength between the hairspring and the inner stud.

[0012] Furthermore, since the molten portions are located on both sides of the spiral spring in the axial direction, even if the axial dimensions of the first and second molten portions are small, the decrease in weld strength due to the wedge effect can be suppressed. Therefore, this configuration is suitable for situations where the amount of heat input during the formation of the molten portions is limited.

[0013] In addition, since the molten section is located on both sides of the hairspring in the axial direction, even if the coating of the paramagnetic hairspring is concentrated at the end of the molten section and the wedge effect is enhanced, the decrease in welding strength can be effectively suppressed.

[0014] The above methods enable the provision of watch parts with paramagnetic hairsprings that can be welded to the inner stud with high strength.

[0015] The watch part according to the second aspect of the present invention may also be an example of the watch part according to the first aspect, wherein an oxide coating is formed on the outer surface of the aforementioned hairspring.

[0016] According to the second scheme, the oxide coating may accumulate at the end of the molten part, but even if the accumulated oxide works in a way that enhances the wedge effect, the decrease in the welding strength of the hairspring and the inner stud can be suppressed because the molten part is located on both sides of the hairspring in the axial direction.

[0017] The watch part according to the third aspect of the present invention may also be the watch part according to the first or second aspect described above, wherein the first molten part and the second molten part are separated from each other along the axial direction.

[0018] According to the third scheme, the fixed part of the hairspring will not be cut off by the molten part, so that the molten part can anchor the hairspring that extends in the circumferential direction, and in particular, can improve the strength of the hairspring in the length direction.

[0019] The watch part according to the fourth aspect of the present invention may also be the watch part according to any of the first to third aspects described above, wherein the aforementioned molten portion is disposed at a position 1 in the circumferential direction relative to the aforementioned inner stud, and the aforementioned first molten portion and the aforementioned second molten portion are continuous along the aforementioned circumferential direction.

[0020] According to the fourth scheme, the first molten part and the second molten part can be formed by a single welding process, thus enabling the production of watch parts with high productivity.

[0021] Furthermore, the configuration with multiple molten sections in the circumferential direction ensures the required weld strength for the hairspring and inner stud by dividing the molten section into multiple molten sections. In contrast, in the fourth embodiment, the molten section is only located at one point in the circumferential direction, thus requiring that single molten section to ensure the required weld strength. Therefore, the effect of effectively improving the weld strength of the hairspring and inner stud can be achieved.

[0022] The watch part according to the fifth aspect of the present invention may also be the watch part according to any of the first to fourth aspects described above, wherein the aforementioned molten part is located on the side opposite to the aforementioned inner stud, sandwiching the aforementioned fixed part.

[0023] According to the fifth scheme, by using the molten section to restrict the displacement of the fixed part of the hairspring in the direction away from the inner stud, it is possible to prevent the hairspring from falling off the inner stud. Therefore, it is possible to effectively and firmly fix the hairspring to the inner stud.

[0024] The watch part according to the sixth aspect of the present invention may also be the watch part according to any of the first to fifth aspects described above, wherein the aforementioned fixed part has a gap in the radial direction relative to the aforementioned inner post.

[0025] In the sixth embodiment, compared with the configuration where the fixed part contacts the inner pile, there is room for displacement of the fixed part relative to the inner pile, and the fixed part is easy to detach from the inner pile. Therefore, it is suitable for the above-mentioned configuration that can improve the welding strength between the hairspring and the inner pile and firmly fix the hairspring to the inner pile.

[0026] The watch part according to the seventh aspect of the present invention may also be a watch part according to the second aspect or any of the above-mentioned aspects, further comprising an aggregate formed by the aforementioned oxide coating and covered by the aforementioned molten portion.

[0027] According to the seventh scheme, even if the aggregate covered by the molten part works in a way that enhances the wedge effect, the decrease in the welding strength of the hairspring and the inner stud can be suppressed because the molten part is located on both sides of the hairspring in the axial direction.

[0028] The watch part according to the eighth aspect of the present invention may also be a watch part according to any of the first to seventh aspects described above, wherein the inner stud has a main body extending in the circumferential direction around the balance shaft, and a gap portion is formed in the inner stud defining the two ends of the main body in the circumferential direction.

[0029] According to Option 8, regarding the inner stud with interference fit for the balance shaft, by providing a gap, the pull-out force and loosening torque can be reduced to appropriate values. Therefore, the installation of the inner stud onto the balance shaft becomes easier, which can improve the productivity of watch movements, including watch parts.

[0030] The watch part according to the ninth aspect of the present invention may also be, in the watch part according to the eighth aspect above, the aforementioned gap portion is located at a position offset from the aforementioned molten portion with respect to the aforementioned balance shaft as the center, and offset from the aforementioned molten portion by a predetermined angle of 180°.

[0031] If the inner stud with the gap is fixed to the balance shaft, the inner stud may sometimes be eccentric relative to the balance shaft, which is its center of rotation, on the side opposite to the gap. According to the ninth embodiment, even if the inner stud is eccentric relative to the center of rotation, the fixed part of the hairspring is unlikely to displace in the radial direction. Therefore, errors in the isochronism of the hairspring can be suppressed. Furthermore, since the gap is provided to avoid the molten part, the stress generated in the inner stud when it is fixed to the balance shaft is unlikely to affect the molten part. Therefore, the decrease in the fixing force of the inner stud and the hairspring in the molten part can be suppressed.

[0032] The watch part according to the 10th aspect of the present invention may also be the watch part according to the 8th or 9th aspect described above, wherein the inner stud is polygonal when viewed from the axial direction.

[0033] According to Option 10, the inner pile can be easily shaped into the desired form, thus making it easy to adjust the center of gravity of the inner pile.

[0034] The watch movement according to the 11th aspect of the present invention includes the watch parts involved in any one of the first to 10th aspects described above.

[0035] According to Option 11, the paramagnetic hairspring is welded to the inner stud with high strength, thus providing a highly reliable watch movement that can suppress damage to the balance wheel and hairspring system.

[0036] The watch according to the 12th aspect of the present invention includes the watch movement according to the 11th aspect described above.

[0037] According to Option 12, highly reliable clocks can be provided.

[0038] The 13th aspect of the present invention relates to a method for manufacturing a watch part having an inner stud fixed to the balance shaft and a hairspring fixed to the inner stud. The hairspring is formed of a paramagnetic material. A pair of rims are provided on the inner stud, which are opposite to the hairspring from both sides in the axial direction. The inner stud and the hairspring are melted by laser welding of the pair of rims and the hairspring, thereby fixing the inner stud and the hairspring to each other.

[0039] According to Scheme 13, the molten portions of each endplate and the hairspring are formed on both sides of the hairspring in the axial direction. Therefore, compared to a configuration where laser welding is performed only at one point on the hairspring and the inner stud, the heat input during laser welding of each endplate can be reduced, while simultaneously increasing the overall volume of the molten portion. This helps to suppress the decrease in the strength of the hairspring itself, while simultaneously improving the weld strength between the hairspring and the inner stud.

[0040] Furthermore, since the molten portions are located on both sides of the spiral spring in the axial direction, even if the axial dimensions of each molten portion are small, the decrease in weld strength due to the wedge effect can be suppressed. Therefore, this configuration is suitable for situations where the amount of heat input during the formation of the molten portions is limited.

[0041] In addition, since the molten section is located on both sides of the hairspring in the axial direction, even if the coating of the paramagnetic hairspring is concentrated at the end of the molten section and the wedge effect is enhanced, the decrease in welding strength can be effectively suppressed.

[0042] Through the above methods, a paramagnetic hairspring can be welded to the inner pile with high strength.

[0043] [The effects of the invention] According to the present invention, a watch part, a watch movement, a watch, and a method for manufacturing a watch part are provided, which can provide a paramagnetic hairspring that is welded to an inner stud with high strength. Attached Figure Description

[0044] Figure 1 This is an external view of the clock according to the first embodiment.

[0045] Figure 2 This is a top view of the movement of the first embodiment.

[0046] Figure 3 This is a top view of the balance wheel and hairspring system of the first embodiment.

[0047] Figure 4 This is a top view showing a portion of the clockwork component according to the first embodiment.

[0048] Figure 5 yes Figure 4 A cross-sectional view of the VV line.

[0049] Figure 6 This is a three-dimensional view of the inner pile before welding in the first embodiment.

[0050] Figure 7 This is a top view showing the state of the spiral spring and inner stud before welding according to the first embodiment.

[0051] Figure 8 yes Figure 7 A cross-sectional view along line VIII-VIII.

[0052] Figure 9 This is a cross-sectional view of a watch part in a modified example of the first embodiment, which is related to... Figure 5 The corresponding diagram.

[0053] Figure 10 This is a longitudinal section view of the internal pile in the second embodiment.

[0054] Figure 11 This is a top view of the balance wheel and hairspring system of the third embodiment.

[0055] Figure 12 This is a top view of the balance wheel and hairspring system in the first variation of the third embodiment.

[0056] Figure 13 This is a top view of the balance wheel and hairspring system in the second variation of the third embodiment.

[0057] Figure 14 This is a top view of the balance wheel and hairspring system of the fourth embodiment.

[0058] Figure 15 This is a top view of the balance wheel and hairspring system in a variation of the fourth embodiment. Detailed Implementation

[0059] Hereinafter, embodiments of the present invention will be described based on the accompanying drawings. Furthermore, in the following description, components having the same or similar functions will be labeled with the same reference numerals. Also, repeated descriptions of these components will sometimes be omitted.

[0060] [First Implementation] Figure 1 This is an external view of the clock according to the first embodiment.

[0061] like Figure 1 As shown, the clock 1 of this embodiment includes, within a clock case 3 having a case back cover (not shown) and a glass 2, a movement 10 (clock movement); a dial 4 having at least a scale indicating information related to the hour; and hands including an hour hand 5 indicating the hour, a minute hand 6 indicating the minute, and a second hand 7 indicating the second.

[0062] Figure 2 This is a top view of the movement of the first embodiment.

[0063] like Figure 2 As shown, the movement 10 has a base plate 11 that forms the base plate. A shank guide hole 11a is formed on the base plate 11. Connected to... Figure 1 The handle 8 shown has a handle shaft 12 that is rotatably inserted into a handle shaft guide hole 11a. The axial position of the handle shaft 12 is determined by a switching device having a shift lever 13, a clutch lever 14, a clutch lever spring 15, and a back-side pusher 16. In addition, a vertical wheel 17 is rotatably provided on the guide shaft portion of the handle shaft 12.

[0064] In this configuration, if the shank 12 is rotated, the vertical wheel 17 rotates via the rotation of a clutch wheel (not shown). If the vertical wheel 17 rotates, the small steel wheel 20 and the large steel wheel 321 rotate sequentially, and the mainspring (not shown) housed in the barrel wheel 22 is wound up. Furthermore, the barrel wheel 22 is axled between the base plate 11 and the barrel clamping plate 23.

[0065] Wheel 25, wheel 26, wheel 27, and escape wheel 35 are supported by an axle between the base plate 11 and the wheel train clamp 24. They are configured such that if the barrel wheel 22 rotates due to the restoring force of the mainspring, wheel 25, wheel 26, and wheel 27 rotate sequentially. These barrel wheels 22, 25, 26, and 27 constitute the dial-side wheel train.

[0066] Furthermore, if wheel 25 rotates, the minute wheel (not shown) rotates based on that rotation, and the minute hand 6 mounted on the minute wheel (see reference) Figure 1 The minute wheel is displayed. Additionally, if the minute wheel rotates, the hour wheel (not shown) rotates via a cross wheel (not shown), and the hour hand 5 (see reference) is mounted on the hour wheel. Figure 1 The display shows the hour. Additionally, the second hand 7 (refer to...) is mounted on the second wheel linked to the fourth wheel 27, and rotates by the fourth wheel 27. Figure 1 Displays "seconds".

[0067] On the side of the movement 10, an escapement / regulating mechanism 30 for controlling the rotation of the side gear train is arranged. The escapement / regulating mechanism 30 includes: an escape wheel 35, which engages with the fourth wheel 27; an escape fork 36, which causes the escape wheel 35 to rotate regularly during escape; and a balance wheel and hairspring system 40. The construction of the balance wheel and hairspring system 40 will be described in detail below.

[0068] Figure 3 This is a top view of the balance wheel and hairspring system of the first embodiment.

[0069] like Figure 3 As shown, the balance wheel and hairspring system 40 includes a balance shaft 41, a balance wheel 42, a hairspring 43, and an inner stud 44. The balance wheel and hairspring system 40 utilizes the power of the hairspring 43 to reciprocate (rotate clockwise and counterclockwise) around the central axis O of the balance shaft 41 with a certain oscillation period (balance angle). Furthermore, in this embodiment, the direction along the central axis O of the balance shaft 41 is referred to as the axial direction, the direction orthogonal to the central axis O and extending radially from the central axis O is referred to as the radial direction, and the direction surrounding the central axis O when viewed from above in the axial direction is referred to as the circumferential direction.

[0070] The balance shaft 41 is a rod-shaped component formed of a metal material such as brass and extending along the central axis O. The two ends of the balance shaft 41 in the axial direction are supported by the base plate 11 and the balance wheel and hairspring system clamp (not shown).

[0071] The balance wheel 42 includes: an annular rim 47 that surrounds the balance shaft 41 from the outer side in the radial direction; and an arm 48 that connects the rim 47 and the balance shaft 41 in the radial direction. The rim 47 is coaxially arranged with respect to the central axis O. The rim 47 is formed of a metal material such as brass. Multiple arms 48 extend radially and are spaced apart in the circumferential direction. In the illustrated example, four arms 48 are arranged at 90-degree intervals around the central axis O. However, the number, arrangement, and shape of the arms 48 are not limited to this.

[0072] The outer ends of each arm 48 in the radial direction are integrally connected to the inner periphery of the rim 47. The inner ends of each arm 48 in the radial direction are connected to each other to form a single unit. At the connecting part where the inner ends of each arm 48 are integrally connected, the approximate central portion of the balance shaft 41 in the axial direction is fixed. Thus, the balance shaft 41 and the balance wheel 42 are fixed to each other to form a watch component 46.

[0073] The hairspring 43 is a thin leaf spring made of metal. The metal material forming the hairspring 43 is a paramagnetic material, and in this embodiment, it is a niobium alloy. An oxide coating may also be formed on the outer surface of the hairspring 43. The hairspring 43 is formed in a spiral shape in a plane orthogonal to the central axis O. The inner end 43a of the hairspring 43 is fixed to the balance shaft 41 via an inner stud 44.

[0074] Except for its outermost circumference, the hairspring 43 extends along an Archimedean curve when viewed axially around the central axis O. The hairspring 43 extends along an Archimedean curve with its inner end 43a as the unwound position, when viewed axially, with the central axis O as the origin of the polar coordinate system. The outermost circumference of the hairspring 43 extends radially outward from the aforementioned Archimedean curve. The outer end of the hairspring 43 is fixed to an outer stud 45, which is mounted via an outer stud clamp (not shown). Hereinafter, the portion of the hairspring 43 extending along the Archimedean curve between the inner end 43a and the outermost circumference will be referred to as the main portion 43b. Furthermore, the axial dimension of the hairspring 43 will be referred to as its width, and its radial dimension as its thickness.

[0075] The inner stud 44 is disposed inside the hairspring 43. The inner stud 44 has a thickness in the axial direction. The inner stud 44 is formed, for example, of stainless steel or nickel, nickel-iron alloy, etc. The inner stud 44 is formed, for example, by lathe machining or LIGA.

[0076] Figure 4 This is a top view showing a portion of the clockwork component according to the first embodiment.

[0077] like Figure 4 As shown, the inner pile 44 surrounds the swing shaft 41 (see reference). Figure 3 The inner pile 44 is annular. The inner pile 44 has an external fixing part 51 and a single support part 52. The external fixing part 51 has an opening that can be externally fitted into the swing shaft 41, and is fixed to the swing shaft 41 (see also...). Figure 3 The support portion 52 protrudes radially outward from the external fixing portion 51. Viewed axially, the support portion 52 tapers radially outward. The inner stud 44, viewed axially, is a polygonal (pentagonal) shape with the support portion 52 as one vertex. The support portion 52 is only provided at one point in the circumferential direction. The support portion 52 supports the inner end portion 43a of the hairspring 43. The inner end portion 43a of the hairspring 43 is an example of a "fixed portion" fixed to the inner stud 44.

[0078] Figure 5 yes Figure 4 A cross-sectional view of the VV line.

[0079] like Figure 5 As shown, the support portion 52 has a base 53 facing the inner circumferential surface of the inner end portion 43a of the hairspring 43. The base 53 has a gap relative to the hairspring 43 in the radial direction. The gap between the base 53 and the hairspring 43 may only be provided in a portion of the circumferential direction. However, the base 53 may also be configured without gap relative to the hairspring 43.

[0080] like Figure 4 and Figure 5 As shown, the molten portion 60, which fixes the inner end portion 43a of the hairspring 43 and the inner stud 44 to each other, is connected to the support portion 52. The molten portion 60 is the part where the hairspring 43 and the inner stud 44 are melted and alloyed. The molten portion 60 has: a first molten portion 60A, which is provided at a position on a first side in the axial direction relative to the inner end portion 43a of the hairspring 43; and a second molten portion 60B, which is provided at a second side in the axial direction relative to the inner end portion 43a of the hairspring 43.

[0081] The first molten portion 60A and the second molten portion 60B overlap in the axial direction. The first molten portion 60A and the second molten portion 60B are continuous along their full circumferential length. The first molten portion 60A and the second molten portion 60B are separated from each other in the axial direction. A portion of the inner end portion 43a of the hairspring 43 and a portion of the support portion 52 are substantially retained and disposed between the first molten portion 60A and the second molten portion 60B. The width of the hairspring 43 located between the first molten portion 60A and the second molten portion 60B is smaller than the width of the main portion 43b.

[0082] The first molten portion 60A and the second molten portion 60B are continuously arranged from the region axially outer of the inner end portion 43a of the hairspring 43 to the region radially outer of the inner end portion 43a of the hairspring 43. That is, the first molten portion 60A and the second molten portion 60B are positioned on the side opposite to the support portion 52 of the inner stud 44, sandwiching the inner end portion 43a of the hairspring 43, and overlap with the inner end portion 43a of the hairspring 43 when viewed from the radially outer side. Furthermore, the first molten portion 60A and the second molten portion 60B extend radially inner from the region axially outer of the inner end portion 43a of the hairspring 43. The first molten portion 60A and the second molten portion 60B are continuously arranged from the region axially outer of the inner end portion 43a of the hairspring 43 to the region radially inner of the inner end portion 43a of the hairspring 43. However, at least one of the first molten portion 60A and the second molten portion 60B may not be disposed in the region inside the radial direction of the inner end portion 43a of the hairspring 43.

[0083] Here, the manufacturing method of watch part 46 will be explained.

[0084] Figure 6 This is a three-dimensional view of the inner pile before welding in the first embodiment. Figure 7 This is a top view showing the state of the spiral spring and inner stud before welding according to the first embodiment. Figure 8 yes Figure 7 A cross-sectional view along line VIII-VIII.

[0085] like Figures 6 to 8 As shown, the support portion 52 of the inner pile 44 before welding has a base 53 and a pair of eaves 54. The base 53 has a support surface 53a facing outward in the radial direction. The support surface 53a is parallel to the axial direction. The support surface 53a faces the inner circumferential surface of the inner end portion 43a of the hairspring 43 across the entire width in the axial direction. The support surface 53a extends in a shape that mimics the shape of the inner end portion 43a of the hairspring 43. For example, the support surface 53a may extend in an arc shape or along an Archimedean curve. However, the support surface 53a may also be a plane.

[0086] A pair of eaves 54 extend radially outward from the base 53. The pair of eaves 54 are located axially outward from the support surface 53a of the support portion 52, protruding radially outward more than the support surface 53a. The spacing between the pair of eaves 54 is equal to the axial width of the inner end portion 43a of the hairspring 43. The pair of eaves 54 have identical shapes and overlap when viewed axially. The eaves 54 taper radially outward when viewed axially. Ideally, the circumferential width W of the base portion of the eaves 54 is more than 2 and less than 10 times the thickness t of the hairspring 43. Ideally, the thickness T of each eave 54 is more than 0.5 and less than 2 times the thickness t of the hairspring 43. Ideally, the radial protrusion length P of the eaves 54, based on the support surface 53a, is more than 70% of the thickness t of the hairspring 43.

[0087] like Figure 7 and Figure 8As shown, when welding the inner stud 44 and the hairspring 43, the inner end portion 43a of the hairspring 43 is positioned between a pair of cornices 54. The inner end portion 43a of the hairspring 43 is positioned along the support surface 53a of the inner stud 44. In the illustrated example, the inner end portion 43a of the hairspring 43 is positioned radially spaced apart from the support surface 53a of the inner stud 44. However, at least a portion of the inner end portion 43a of the hairspring 43 may also contact the support surface 53a of the inner stud 44. In this case, ideally, the cornices 54, when viewed from the axial direction, cover more than 70% of the inner end portion 43a of the hairspring 43 in its thickness direction (radial direction). In this embodiment, the protruding length P of the cornices 54 is greater than the thickness t of the hairspring 43, and the cornices 54, when viewed from the axial direction, cover the inner end portion 43a of the hairspring 43 along its entire thickness direction. The inner end 43a of the hairspring 43 has two axially oriented end edges that approach or contact the eaves 54 from the inner side in the axial direction.

[0088] In this state, a laser is irradiated toward the support portion 52 of the inner pile 44 to transfer heat to each eave 54, performing laser welding on the inner pile 44 and the hairspring 43. The laser L irradiates toward the inner pile 44 from both outer sides in the axial direction. For example, the laser spot of L may irradiate only the eave 54, only the base 53, or the area spanning from the base 53 to the eave 54. However, ideally, the laser L does not irradiate the hairspring 43.

[0089] By introducing heat into the rim 54, the portion of the rim 54 and the hairspring 43 near the rim 54 melts and alloys, forming a molten portion 60. In this embodiment, the entire rim 54 disappears due to the transformation into the molten portion 60. However, only a portion of the rim 54 may be transformed into the molten portion 60. By forming the molten portion 60, the two axially oriented end edges of the inner end portion 43a of the hairspring 43 recede axially inward. For example, the portion of the inner end portion 43a of the hairspring 43 with the largest receding distance recedes axially inward relative to the axially oriented end edge of the main portion 43b of the hairspring 43 by a distance of 15% to less than 50% of the width of the main portion 43b of the hairspring 43.

[0090] As explained above, the watch part 46 of this embodiment includes a fusion portion 60, which is a fusion portion that fuses the inner stud 44 and the hairspring 43 to fix the inner stud 44 and the inner end portion 43a to each other. The fusion portion 60 has: a first fusion portion 60A, which is provided at a position on a first side in the axial direction relative to the inner end portion 43a; and a second fusion portion 60B, which is provided at a position on a second side in the axial direction relative to the inner end portion 43a. According to this configuration, the hairspring 43 is fixed to the inner stud 44 on both sides in the axial direction. Therefore, compared with the configuration in which the hairspring is fixed to the inner stud by a single fusion portion, the amount of heat input to the hairspring 43 when forming the first fusion portion 60A and the second fusion portion 60B can be reduced, while the overall volume of the fusion portion 60 can be increased. Therefore, the decrease in the strength of the hairspring 43 itself can be suppressed, while the welding strength between the hairspring 43 and the inner stud 44 can be improved.

[0091] Furthermore, since the molten portions 60 are provided on both sides of the spiral spring 43 in the axial direction, even if the axial dimensions of the first molten portion 60A and the second molten portion 60B are small, the decrease in weld strength caused by the wedge effect can be suppressed. Therefore, this configuration is suitable for situations where the amount of heat input during the formation of the molten portions 60 is limited.

[0092] Furthermore, since the molten portion 60 is provided on both sides of the hairspring 43 in the axial direction, even if the coating of the paramagnetic hairspring 43 is concentrated at the end of the molten portion 60 and the wedge effect is enhanced, the decrease in welding strength can be effectively suppressed.

[0093] Through the above, a watch part 46 can be provided, in which a paramagnetic hairspring 43 is welded to the inner stud 44 with high strength.

[0094] Furthermore, regarding the manufacturing method of the watch part 46 in this embodiment, the hairspring 43 is formed of a paramagnetic material, and a pair of cornices 54 opposite to the hairspring 43 are provided on both sides of the inner stud 44 in the axial direction. The inner stud 44 and the hairspring 43 are laser-welded together, melting the cornices 54 and fixing them together. According to this manufacturing method, the molten portions 60 formed by the melting of each cornice 54 and the hairspring 43 are formed on both sides of the hairspring 43 in the axial direction. Therefore, compared to a configuration where only one point of laser welding is performed between the hairspring 43 and the inner stud 44, the heat input during laser welding of each cornice 54 can be reduced, while simultaneously increasing the overall volume of the molten portions 60. Thus, the aforementioned effects are achieved.

[0095] An oxide coating is formed on the outer surface of the hairspring 43. According to this configuration, the oxide coating may accumulate at the end of the molten portion 60, but even if the accumulated oxides act in a way that enhances the wedge effect, since the molten portion 60 is provided on both sides of the hairspring 43 in the axial direction, the decrease in the welding strength between the hairspring 43 and the inner stud 44 can be suppressed.

[0096] The first molten section 60A and the second molten section 60B are separated from each other in the axial direction. According to this configuration, the inner end 43a of the hairspring 43 will not be cut off by the molten section 60, so the molten section 60 anchors the hairspring 43 that extends in the circumferential direction, and in particular, it can improve the strength of the hairspring 43 in the longitudinal direction.

[0097] The first molten portion 60A and the second molten portion 60B are each disposed at a position 1 in the circumferential direction relative to the inner stud 44, and are continuous in the circumferential direction. According to this configuration, each of the first molten portion 60A and the second molten portion 60B can be formed by a single welding, thus enabling the production of watch parts 46 with excellent productivity.

[0098] Furthermore, the configuration with multiple molten portions in the circumferential direction allows the required weld strength for the hairspring and inner stud to be ensured by dividing the molten portion into multiple molten portions. In contrast, in this embodiment, the molten portion 60 is only provided at one location in the circumferential direction, thus requiring that one molten portion 60 to ensure the required weld strength. Therefore, the effect of improving the weld strength of the hairspring 43 and inner stud 44 can be effectively achieved.

[0099] The molten portion 60 is positioned on the side opposite to the inner stud 44, sandwiching the inner end portion 43a. With this configuration, the molten portion 60 restricts the displacement of the inner end portion 43a of the hairspring 43 in the direction away from the inner stud 44, thus preventing the hairspring 43 from detaching from the inner stud 44. Therefore, the hairspring 43 can be securely fixed to the inner stud 44.

[0100] The inner end portion 43a of the hairspring 43 has a gap in the radial direction relative to the inner stud 44. In this configuration, compared to a configuration where the inner end portion 43a of the hairspring 43 is in contact with the inner stud 44, there is room for displacement of the inner end portion 43a relative to the inner stud 44, making it easier for the inner end portion 43a to detach from the inner stud 44. Therefore, it is possible to effectively improve the welding strength between the hairspring 43 and the inner stud 44, thus firmly fixing the hairspring 43 to the inner stud 44.

[0101] Furthermore, when welding the inner stud 44 and the hairspring 43, the rim 54 is arranged such that, when viewed from the axial direction, the inner end 43a of the hairspring 43 covers more than 70% of its thickness direction, thereby enabling the molten inner stud 44 to overlap entirely with the hairspring 43 in its thickness direction. Therefore, the welding strength between the hairspring 43 and the inner stud 44 can be improved.

[0102] Furthermore, by making the circumferential width W of the base end of the eaves 54 more than 2 to 10 times the thickness t of the hairspring 43, and making the thickness T of each eaves 54 more than 0.5 to 2 times the thickness t of the hairspring 43, the eaves 54 can be preferentially melted during laser welding. If the dimensions of each part of the eaves 54 exceed the above-mentioned range, melting of the eaves 54 will require time, and the heat input to the hairspring 43 may increase. Conversely, if the dimensions of each part of the eaves 54 are less than the above-mentioned range, heat transfer from the eaves 54 to the hairspring 43 becomes excessive, and the heat input to the hairspring 43 may increase. Therefore, by keeping the dimensions of each part of the eaves 54 within the above-mentioned range, the heat input to the hairspring 43 can be reduced, suppressing a decrease in the strength of the hairspring 43 itself.

[0103] The inner pile 44 is polygonal when viewed from the axial direction. Based on this configuration, the inner pile 44 can be easily shaped into the desired form, thus making it easy to adjust the center of gravity of the inner pile 44.

[0104] Furthermore, the movement 10 and watch 1 of this embodiment are equipped with the aforementioned watch parts 46, thus enabling the watch parts 46 and watch 1 to have high reliability in suppressing damage to the balance wheel and hairspring system.

[0105] In addition, such as Figure 9 As shown, in the watch part 46, an agglomerate 70 formed by the oxide coating of the hairspring 43 can also be formed by covering the molten portion 60. The agglomerate 70 is located, for example, between the support surface 53a of the hairspring 43 and the inner stud 44. Even if the agglomerate 70 acts in a way that enhances the wedge effect, the molten portion 60 is provided on both sides of the hairspring 43 in the axial direction, which can suppress the decrease in the welding strength between the hairspring 43 and the inner stud 44.

[0106] [Second Implementation] Next, refer to Figure 10 The second embodiment will now be described. The second embodiment differs from the first embodiment in that the point where the inner pile 44A is formed allows for a change in the spacing between the pair of eaves 54. However, the configuration is the same as the first embodiment except as described below.

[0107] Figure 10 This is a longitudinal section view of the internal pile in the second embodiment.

[0108] like Figure 10As shown, the inner pile 44A is formed in a manner that allows it to substantially divide the inner pile 44 of the first embodiment along the axial direction. The inner pile 44A has a first portion 80 and a second portion 81 that are joined together. The relative position of the first portion 80 and the second portion 81 in the axial direction can be adjusted at least during assembly. The first portion 80 and the second portion 81 cooperate to form the base 53 of the support portion 52. Each of the first portion 80 and the second portion 81 has an eave 54. Furthermore, the materials used to form the first portion 80 and the second portion 81 may be the same or different from each other.

[0109] The first part 80 has a cylindrical portion 80a protruding towards the second part 81 along the axial direction. The cylindrical portion 80a is formed in a cylindrical shape coaxial with the central axis O, and an external fixing portion 51 is formed along its entire length in the axial direction. In the second part 81, an insertion hole 81a is formed that extends through in the axial direction. The cylindrical portion 80a is inserted into the insertion hole 81a, and the first part 80 and the second part 81 are joined together. By inserting the cylindrical portion 80a into the insertion hole 81a, the relative displacement of the first part 80 and the second part 81 in a direction orthogonal to the axial direction is restricted. Furthermore, for example, by pressing the cylindrical portion 80a into the insertion hole 81a, the relative displacement of the first part 80 and the second part 81 in the axial direction is restricted. By adjusting the insertion amount of the cylindrical portion 80a relative to the insertion hole 81a, the spacing between the pair of eaves 54 can be changed.

[0110] In this embodiment, the same effect as in the first embodiment is achieved. In addition, in this embodiment, the inner stud 44A has a first portion 80 and a second portion 81 that are joined together. The relative position of the first portion 80 and the second portion 81 in the axial direction can be adjusted. With this configuration, the spacing between the pair of eaves 54 can be changed in accordance with the width of the hairspring, thus enabling the creation of inner studs for various types of hairsprings with different widths. Furthermore, when welding the hairspring 43 and the inner stud 44A, with the inner end portion 43a of the hairspring 43 positioned between the pair of eaves 54, the spacing between the pair of eaves 54 can be reduced, allowing each eave 54 to contact the end edge of the hairspring 43. Therefore, a molten portion 60 can be reliably formed.

[0111] Furthermore, in the second embodiment described above, the cylindrical portion 80a is cylindrical, but it can also be square. In this case, the relative rotation between the first portion 80 and the second portion 81 can be restricted, making it easier to manufacture the inner pile 44A.

[0112] In addition, in the second embodiment described above, a cylindrical portion 80a is provided in the first part 80 and an insertion hole 81a is formed in the second part 81, but the positional relationship between the cylindrical portion and the insertion hole can also be reversed.

[0113] [Third Implementation] Next, refer to Figure 11The third embodiment will now be described. The third embodiment differs from the first embodiment in that the slit is formed at the point on the inner pile 144. However, the configuration is the same as the first embodiment except as described below.

[0114] Figure 11 This is a top view of the balance wheel and hairspring system of the third embodiment.

[0115] like Figure 11 As shown, the inner pile 144 has a pivot shaft 41 (refer to...) Figure 3 The inner pile 144 has a main body 56 extending circumferentially around it. The main body 56 extends less than 360° circumferentially. In the inner pile 144, gaps 57 are formed at both ends of the main body 56 in the circumferential direction. The gaps 57 can also be referred to as slits. The gaps 57 penetrate the inner pile 144 radially and axially, connecting the interior and exterior of the inner pile 144 radially. The gaps 57 expand at regular intervals.

[0116] The gap 57 is located at a position offset from the molten section 60 with respect to the pivot axis 41. Furthermore, the gap 57 is located at a position offset from the molten section 60 by a predetermined angle of 180° with respect to the pivot axis 41. That is, the gap 57 is located at a position further offset from the molten section 60 by an angle range R of 180° with respect to the central axis O. In this embodiment, the gap 57 is located at a position offset less than 90° further from 180° with respect to the molten section 60 with respect to the pivot axis 41. The gap 57 penetrates the radially thin portion of the inner pile 144. Additionally, the portion of the inner pile 144 offset by 180° relative to the gap 57 is a location with extremely small radial thickness.

[0117] In this embodiment, the same effect as in the first embodiment is achieved. In addition, in this embodiment, gaps 57 are formed at both ends of the main body 56 in the circumferential direction of the inner stud 144. With this configuration, the inner stud 144, which has an interference fit with the balance shaft 41, can have its pull-out force and loosening torque reduced to appropriate values ​​by providing the gaps 57. Therefore, the installation of the inner stud 144 onto the balance shaft 41 becomes easier, and the productivity of the movement 10, including the watch parts 46, can be improved.

[0118] If the inner stud 144, which has the gap 57, is fixed to the balance shaft 41, the inner stud 144 may sometimes be eccentric relative to the balance shaft 41, which is its center of rotation, to the side opposite to the gap 57. In this embodiment, the gap 57 is positioned at a predetermined angle offset from the molten section 60 by 180°. According to this configuration, even if the inner stud 144 is eccentric relative to the center of rotation (central axis O), the inner end portion 43a of the hairspring 43 is unlikely to displace in the radial direction. As a result, errors in the isochronism of the hairspring 43 can be suppressed. Furthermore, the gap 57 is offset relative to the molten section 60 with the balance shaft 41 as the center. As a result, the gap 57 is provided to avoid the molten section 60, and the stress generated in the inner stud 144 when it is fixed to the balance shaft 41 is unlikely to affect the molten section 60. Therefore, the decrease in the fixing force of the inner stud 144 and the hairspring 43 in the molten section 60 can be suppressed.

[0119] The inner pile 144 is polygonal when viewed from the axial direction. This configuration allows the inner pile 144 to be easily shaped into a desired form, thus facilitating the adjustment of its center of gravity. Specifically, in this embodiment, a gap 57 is provided in the inner pile 144, positioned at a predetermined angle offset from the molten portion 60 by 180° about the pivot axis 41. Therefore, the inner pile 144 does not exhibit symmetry in its top-view shape. This effectively facilitates the adjustment of the inner pile 144's center of gravity.

[0120] Furthermore, in the third embodiment described above, the gap portion 57 is located at a position offset by less than 90° from 180° relative to the molten portion 60, centered on the pivot axis 41. However, as... Figure 12 As shown, the gap 57 can also be positioned at a point offset by more than 90° from 180° relative to the molten portion 60, centered on the pivot axis 41. Additionally, as... Figure 13 As shown, the gap 57 can also be positioned 180° off from the molten section 60 with the pivot axis 41 as the center.

[0121] [Fourth Implementation] Next, refer to Figure 14 The fourth embodiment will now be described. The fourth embodiment differs from the third embodiment in that the inner pile 244 appears as a droplet when viewed from the axial direction. However, the configuration is the same as the third embodiment except as described below.

[0122] Figure 14 This is a top view of the balance wheel and hairspring system of the fourth embodiment.

[0123] like Figure 14As shown, the inner pile 244, viewed axially, is teardrop-shaped with the molten portion 60 (support portion 52) as its apex. The gap portion 57 of the inner pile 244 is positioned offset from the molten portion 60 with respect to the pivot axis 41. Furthermore, the gap portion 57 is positioned offset from the molten portion 60 by a predetermined angle of 180° with respect to the pivot axis 41. In this embodiment, the gap portion 57 is positioned offset by less than 90° further from 180° with respect to the molten portion 60 with respect to the pivot axis 41.

[0124] In this embodiment, the same effect as in the third embodiment is achieved. Furthermore, as... Figure 15 As shown, in the droplet-shaped inner pile 244, the gap 57 can also be positioned 180° off from the molten part 60 with the pivot axis 41 as the center.

[0125] Furthermore, the present invention is not limited to the embodiments described above with reference to the accompanying drawings, and various modifications can be considered within its technical scope.

[0126] For example, in the above embodiment, the molten portion 60 is disposed in the region radially outer of the inner end portion 43a of the hairspring 43, but this configuration is not limited. That is, at least one of the first molten portion and the second molten portion may not be disposed in the region radially outer of the inner end portion 43a of the hairspring 43.

[0127] In the above embodiment, the first molten portion 60A and the second molten portion 60B are separated from each other in the axial direction, but a portion of each of the first molten portion and the second molten portion can be continuous with each other.

[0128] Furthermore, in the above embodiments, niobium alloy is used as an example of the paramagnetic material forming the hairspring 43, but the paramagnetic material forming the hairspring is not limited to niobium alloy. As long as it is a material with a melting point of more than 1800°C, the above-mentioned effects can be effectively achieved.

[0129] Furthermore, without departing from the spirit of the present invention, the constituent elements in the above embodiments can be appropriately replaced with well-known constituent elements. In addition, the above embodiments and variations can be appropriately combined.

[0130] [Explanation of reference numerals in the attached figures] 1……Clock 10……Movement (Clock Movement) 41……Balance Axis 43……Hair Spring 44, 44A, 144, 244……Inner Stud 46……Clock Parts 54……Ceiling 56……Main Body 57……Gap 60……Melting Section 60A……First Melting Section 60B……Second Melting Section 70……Aggregate.

Claims

1. A watchmaking component, comprising: The inner stake is fixed to the swing axis; A hairspring, formed of a paramagnetic material, has a fixed portion fixed to the inner stud; and The molten section is the part in which the inner stud and the hairspring are melted together to fix the inner stud and the fixed part to each other. The molten portion has: A first molten portion, which is positioned on a first side relative to the axial direction of the fixed portion; and The second molten portion is located on the second side relative to the axial direction of the fixed portion.

2. The watch part according to claim 1, wherein, An oxide coating is formed on the outer surface of the hairspring.

3. The watchmaking part according to claim 1 or claim 2, wherein, The first molten portion and the second molten portion are separated from each other along the axial direction.

4. The watchmaking part according to claim 1 or claim 2, wherein, The molten portion is positioned at point 1 in the circumferential direction relative to the inner pile. The first molten portion and the second molten portion are continuous along the circumferential direction, respectively.

5. The watchmaking part according to claim 1 or claim 2, wherein, The molten portion is located on the side opposite to the inner pile, sandwiching the fixed portion.

6. The watchmaking part according to claim 1 or claim 2, wherein, The fixed part has a gap in the radial direction relative to the inner pile.

7. The watch part according to claim 2, wherein, It also includes an aggregate formed by the oxide coating and covered by the molten portion.

8. The watch part according to claim 1, wherein, The inner pile has a main body extending circumferentially around the pendulum axis. The inner pile has gaps at both ends in the circumferential direction of the main body.

9. The watch part according to claim 8, wherein, The gap is located at a position offset from the molten part with respect to the pivot axis, and offset from the molten part by a predetermined angle of 180°.

10. The watchmaking part according to claim 8 or claim 9, wherein, The inner pile is polygonal when viewed from the axial direction.

11. A watch movement comprising a watch component according to claim 1, claim 2 or claim 8.

12. A clock or watch comprising a clock or watch movement according to claim 11.

13. A method for manufacturing a watch part, comprising a watch part having an inner stud fixed to a balance shaft and a hairspring fixed to the inner stud. The hairspring is formed of a paramagnetic material. The inner pile is provided with a pair of eaves on both sides in the axial direction opposite to the hairspring. By laser welding the pair of eaves and the hairspring, the inner pile and the eaves are melted together, thus fixing the inner pile and the hairspring to each other.

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